Creating a new download is a two step process.
You must first create a new download resource using this call here.
After that you take the return Pithub::Result object and call "upload" to upload the file to Amazon S3.

Upload a file to Amazon S3. See also: "create". This will use the ua attribute's request method to do a POST request to Amazon S3. It requires the Pithub::Result object of a "create" call to get the necessary data for S3 API call. This method returns an HTTP::Response object directly, not a Pithub::Result object (like all other methods do)! If the upload was successful the status will be 201.